Todd Horowitz: Attention, motion, and trajectories
Talk by Todd Horowitz of Harvard Medical School for the Redwood Center for Theoretical Neuroscience, on November 30, 2007 at UC-Berkeley.
Much of our current understanding of visual attention is built on experimental paradigms that can be characterized as either static or as a series of brief, discontinuous snapshots. However, in our everyday environment, objects around us move smoothly, or we move with respect to the environment. Recent research has tried to capture dynamic and continuous nature of real world tasks. With static objects, it has been demonstrated that spatial location is an important cue for deploying attention. with dynamic objects, however, location changes over time. Extending spatial position into the time domain gives us a trajectory. Is trajectory information employed in directing attention? I will present three sets of studies, using the visual search and multiple object tracking (MOT) paradigms, testing for evidence that attention accesses trajectory information. First, I use a search asymmetry technique to determine whether different types of trajectories (random walk, ballistic, and composite) can guide attention. Second, I use a modified MOT technique to demonstrate that the visual system encodes the direction of attended objects. Finally , I use another modified MOT design, "tracking across the gap", to evaluate whether observers can predict the future locations of attended objects.